View single post by NigelK
 Posted: 11-22-2014 10:51 pm
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NigelK

 

Joined: 07-16-2014
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Hi Eric

An Accuspark points replacement unit was fitted to my GT a few weeks back. At around the same time I re-installed the refurbished original stereo and was getting serious RFI. The guys who had installed the Accuspark said there was too much RFI from the ignition system for their dyno to get accurate readings.

So I decided to change the coil, which prompted hours of internet research into ballasted and non-ballasted systems. The consensus view was that i) GTs and late Jensen-Healeys have a resistor wire, ii) earlier Jensen-Healeys have a ballast resistor mounted on the bulkhead, iii) using a 3 ohm coil with a ballast resistor or wire is not a good idea as you will get a weak spark, iv) if you have a ballast resistor or wire you need to use a 1.5 ohm coil, and v) if you have a ballast resistor or wire you must connect the +ve feed to the points replacement unit on the +ve side of the resistor.

A PO had removed the resistor wire from my GT, but there was still the ballast system wire from the starter motor to the coil, as per the wiring diagram (which has no resistor on it). Confusing! So I installed a 3 ohm Accuspark coil, connected the live feed from the tach to one +ve terminal and the wire from the starter motor to the other +ve terminal, and ran the +ve feed to the points replacement unit direct to an ignition live on the fusebox. This seems to work, even though the feed from the starter motor is probably redundant. The RFI issue seems to have been fixed by replacing the stock Champion N9YC plugs with NGK BPR6ES resistor plugs.

Hope this helps.

Best wishes,
Nigel